We consider the problem where $W$ invades the $(U,V)$ system in the three species Lotka-Volterra competition-diffusion model.
Numerical simulation indicates that the presence of $W$ can dramatically change the competitive interaction between
$U$ and $V$ in some parameter range if the invading $W$ is not too small.
We also construct exact travelling wave solutions with non-trivial three components and track
the bifurcation branches of these solutions by AUTO.